Speeding up audio or speech generally results in change of pitch and decreased quality. Previous inventions were complex in their methods to protect the integrity of the original information.
When the playback speed of audio increases, the pitch increases respectively. According to the Similarity Theorem, decreased time (increased playback rate) results in higher frequencies which translates to higher pitch (Zonst 1995). This phenomenon is illustrated when a 331/3 RPM record is played at 78 RPM. Not only is the resulting sound difficult to understand, but the speaker also is unidentifiable, sounding like a chipmunk.
An alternative method to achieve this goal is to remove data at a fixed sampling rate, whether the data is redundant (duplicate) or original. Other methods use more complex and process time consuming methods by performing an inverse mathematical manipulation such as an inverse Fourier transform to recreate the shortened information. A variety of encoding methods are used for transmitting audio signals that are not easily manipulated for speeding up the original signal. Simpler approaches which just eliminate periods of silence do not produce a quality result.
In general, while these other inventions examine various aspects of the objective of this invention, they have not provided a satisfactory conclusion of the combination of simplicity and quality.